A new Kriging–Bat Algorithm for solving computationally expensive black-box global optimization problems

Many global optimization (GO) algorithms have been introduced in recent decades to deal with the Computationally Expensive Black-Box (CEBB) optimization problems. The high number of objective function evaluations, required by conventional GO methods, is prohibitive or at least inconvenient for practical design applications. In this work, a new Kriging–Bat algorithm (K–BA) is introduced for solving CEBB problems with further improved search efficiency and robustness. A Kriging surrogate model (SM) is integrated with the Bat Algorithm (BA) to find the global optimum using substantially reduced number of evaluations of the computationally expensive objective function. The new K–BA algorithm is tested and compared with other well-known GO algorithms, using a set of standard benchmark problems with 2 to 16 design variables, as well as a real-life engineering optimization application, to determine its search capability, efficiency and robustness. Results of the comprehensive tests demonstrated the suitability and superior capability of the new K–BA.     

Fabrication of polypyrrole composite on perlite zeolite surface and its application for removal of copper from wood and paper factories wastewater

The large volumes of water used in wood and paper industries produce substantial amounts of wastewater. These industries are among the most polluting ones in the world; there are large quantities of heavy metals (copper, iron, zinc, etc.) and dyes in the wastewater of these industries, and this wastewater has high levels of COD and BOD. We studied copper removal from the effluents of a wood and paper factory by using a polypyrrole composite consisting of natural Zeolite coated on Perlite (PPy/Perlite). The experiments were performed in a batch system in which effects of various parameters including pH, contact time, adsorbent dosage, and temperature on adsorption were studied. Moreover, SEM and FTIR were employed to identify the structure of the synthesized adsorbent. Results indicated that the maximum copper removal (95%) happened at pH=6, contact time of 12 minutes, and adsorbent dose of 0.4 g/100 mL of the wastewater. Furthermore, copper adsorption capacity of the PPy/Perlite adsorbent improved with increases in temperature and reached its peak at 40 °C. Values of the thermodynamic variables (ΔS, ΔH, ΔG) indicated that copper adsorption could occur in the temperature range of 293-323 Kelvin, and was spontaneous and endothermic. Equilibrium information in the studied range of the initial concentrations of copper and in the temperature range suitably matched the Freundlich isotherm. Evaluation of experimental information for studying the kinetics of copper adsorption by PPy/Perlite revealed that copper adsorption followed the pseudo-second-order kinetic model.     

Nonlinear dielectric thin films for high-power electric storage with energy density comparable with electrochemical supercapacitors

Although batteries possess high energy storage density, their output power is limited by the slow movement of charge carriers, and thus capacitors are often required to deliver high power output. Dielectric capacitors have high power density with fast discharge rate, but their energy density is typically much lower than electrochemical supercapacitors. Increasing the energy density of dielectric materials is highly desired to extend their applications in many emerging power system applications. In this paper, we review the mechanisms and major characteristics of electric energy storage with electrochemical supercapacitors and dielectric capacitors. Three types of in-house-produced ferroic nonlinear dielectric thin film materials with high energy density are described, including (Pb(0.97)La(0.02))(Zr(0.90)Sn(0.05)Ti(0.05))O(3) (PLZST) antiferroelectric ceramic thin films, Pb(Zn(1/3)Nb(2/3))O(3-)Pb(Mg(1/3)Nb(2/3))O(3-)PbTiO(3) (PZN-PMN-PT) relaxor ferroelectric ceramic thin films, and poly(vinylidene fluoride) (PVDF)-based polymer blend thin films. The results showed that these thin film materials are promising for electric storage with outstandingly high power density and fairly high energy density, comparable with electrochemical supercapacitors.     

A 0.5 V offset cancelled latch comparator in standard 0.18 μm CMOS process

This paper presents a new 0.5 V high-speed dynamic latch comparator with built-in foreground offset cancellation capability and rail-to-rail input range. Traditional latch comparators lose their speed performance in low voltage condition, especially in sub-1V applications. The proposed latch comparator utilizes a speed-up technique based on a novel boosting method to mitigate the low voltage imperfections on circuit operation. Employing a new offset cancellation technique based on the same boosting capacitors is another key idea. This enhances the accuracy of the ultra low-voltage latch comparators and relaxes the need for preamplifier stage, which is conventionally used in the low offset latch comparator. The performed Monte Carlo simulations over corners in 0.18 μm standard CMOS process show the improvement of input referred offset voltage with a standard deviation of 29.9 mV/299 μV before and after offset cancellation, respectively. The designed comparator dissipates 34 μW power from 0.5 V voltage supply while operating in 200 MHz clock frequency and detects 1 mV input difference.     

Life cycle assessment of oxygen-18 production using cryogenic oxygen distillation

In this study, life cycle assessment of oxygen-18 by using cryogenic distillation of oxygen is performed using SimaPro 8.3 software. Life cycle assessment is performed to understand the environmental profile and hotspots of this process in order to be used in design and development. Simulation of oxygen-18 process is executed by Hysys software, and the required inputs and outputs for inventory of life cycle were acquired. By doing life cycle assessment and considering achieved results after characterization and normalization of inventory data it has been investigated that in the majority of environmental impacts electricity consumption has a huge contribution relative to other parts of the system like liquefied oxygen production from air separation unit, required facilities for air separation and oxygen-18 units, and needed transportation. Also, among 17 impact categories investigated in ReCiPe impact assessment method, fossil depletion, climate change (human health), particulate matter formation, climate change (ecosystem), human toxicity, and metal depletion have the most contribution in entire environmental loads respectively. Furthermore, sensitivity analysis showed that changing life cycle impact assessment method from ReCiPe to IMPACT 2002 + has no significant effect on acquired results and results are confident. In addition, assumption of market for depleted oxygen from heavy isotopes which is withdrawn from top of distillation columns showed some positive effects compared to first case and environmental impacts resulted from liquefied oxygen production (feed) reduced but because of huge contribution of electricity consumption compared to other sections, this positive effect has no remarkable influence on entire environmental loads of product system.     

Innovative Diagnostic Peptide-Based Technologies for Cancer Diagnosis: Focus on EGFR-Targeting Peptides

Active targeting using biological ligands has emerged as a novel strategy for the targeted delivery of diagnostic agents to tumor cells. Conjugating functional targeting moieties with diagnostic probes can increase their accumulation in tumor cells and tissues, enhancing signal detection and, thus, the sensitivity of diagnosis. Due to their small size, ease of chemical synthesis and site-specific modification, high tissue penetration, low immunogenicity, rapid blood clearance, low cost, and biosafety, peptides offer several advantages over antibodies and proteins in diagnostic applications. Epidermal growth factor receptor (EGFR) is one of the most promising cancer biomarkers for actively targeting diagnostic and therapeutic agents to tumor cells due to its active involvement and overexpression in various cancers. Several peptides for EGFR-targeting have been identified in the last decades, which have been obtained by multiple means including derivation from natural proteins, phage display screening, positional scanning synthetic combinatorial library, and in silico screening. Many studies have used these peptides as a targeting moiety for diagnosing different cancers in vitro, in vivo, and in clinical trials. This review summarizes the progress of EGFR-targeting peptide-based assays in the molecular diagnosis of cancer.     

Power and energy consumption of skid-steer rovers turning on loose soil

This study highlights two key phenomena affecting power and energy consumption of skid-steer rovers on loose soil that is not present on the hard ground: soil excavation due to wheel counterrotation and impeded turning when dragging a braked wheel. Experiments in the field and in a controlled laboratory sandbox show that, on sand, power peaks by 15%–20% in a newly identified range of turns with radii between half the rover width, $B∕2$, to $R^{\prime }$, the radius at which the inner wheel does not turn. In this range of turns, the inner wheels rotate backwards but are being dragged forward through piles of sand they excavate by counterrotation. At $R\prime$, turns are shown to take much longer, leading to higher total energy consumption over time. Experiments in a controlled laboratory sandbox isolate the high motor torque and the resistance force experienced when a skid-steer rover drags a counterrotating or braked wheel, respectively, through loose soil. Other field experiments also demonstrate that paths combining circular arcs and lines can lead to energy savings of up to 15% relative to common ones consisting of point turns and lines; the experimental results suggest the circular arcs should have radii of approximately $2R\prime$. The quantitative values presented in this paper are specific to the rover and soils tested, but there are reasons to support the overall conclusions generalizing to all skid-steer rovers in loose soil.